Workpiece transfer mechanism for use with assembling machines and the like



April 23, 1968 P. H. DIXON WORKPIECE TRANSFER MECHANISM FOR USE WITH ASSEMBLING MACHINES AND THE LIKE Filed Marsh 29, 1966 8 Sheets-Sheet 1 MVEJVJTORJ .Dcxoh.)

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WORKPIECE TRANSFER MECHANISM FOR USE WITH ASSEMBLING 4 MAC HINES AND THE LIKE Filed March 29, 1966 8 Sheets-Sheet 2 (3-5 2;; *m 102 -uz L fl -m .6, pig-s O3 I: I04- l i ll Q i 1' J05 5 l )06 w l E 5 H )05 6H3 5 3 H4- 1 y i t 1- i i i r 84 I00 i Q I @z i 5a a4 5 I AZ w 5 A ril 23, 1968 P. H. DIXON WORKPIECE TRANSFER MECHANISM FOR USE WITH ASSEMBLING MACHINES AND THE LIKE 8 Sheets-Sheet 5 Filed March 29, 1966 J MVEIMTQKJ paul HlDixom A Zd fW Va 0am) OTTORMEYW 3,378,907 MBLING P. H. DIXON April 23, 1968 WORKPIECE TRANSFER MECHANISM FOR USE WITH ASSE MACHINES AND THE LIKE 8 Sheets-Sheet 4 E MVSMTOK, awl Q4. ID :1 X0 ru A, 420%Mkbl, wk: W UTTORMEZYJ Filed March 29, 1966 April 23, 1968 P. H. DIXON 3,378,907

HANISM FOR USE WITH ASSEMBLING ES AND THE LIKE WORKPIECE TRANSFER MEC MACHIN 8 Sheets-Sheet 5 Filed March 29, 1966 l Z0 Keg. $3

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4 WORKPIECE TRANSFER MECHANISM FOR USE WITH ASSEMBLING MACHINES AND THE LIKE Filed March 29, 1966 8 Sheets Sheet 6 IZI 134 72 IZA 0 I[ T 8 72 As I35 I34 1 I36 1 124 13a 0 I3! x Wu) Q-LDixor ,g, .w zamw yer (M A 'r'fo nroEYw April 23, 1968 P. H. DiXON 3,378,907

WORKPIECB TRANSFER MECHANISM FOR USE WITH ASSEMBLING MACHINES AND THE LIKE 8 Sheets-Sheet 7 Filed March 29, 1966 Yaw-row Paul @4- 33 5 V 41% W VJIQMQ Cfi-n'onwsyw April 23, 1968 P. H. DIXON WORKPIECE TRANSFER MECHANISM FOR USE WITH ASSEMBLING MACHINES AND THE LIKE Filed March 29, 1966 8 Sheets-Sheet a vfiw-rok/ pawl w% 34.1) ixoru n oq-rwomwavw United States Patent WORKPIECE TRANSFER MECHANISM FOR USE WITH ASSEMBLING MACHINES AND THE LIKE Paul H. Dixon, Rockford, Ill., assignor to Dixon Automatic Tool, Inc., Rockford, Ill., a corporation of Illinois Filed Mar. 29, 1966, Ser. No. 538,288 10 Claims. (Cl. 29-403) This invention relates generally to an improved transfer mechanism and, more particularly, to an improved transfer mechanism capable of feeding individual workpieces to a continuous assembling machine.

It is a primary object of the present invention to provide an improved transfer mechanism for transferring individual workpieces from a fixed feeding station to a plurality of continuously rotating work stations. A related object is to provide such a transfer mechanism which operates continuously in synchronism with the continuously rotating work stations so that a workpiece is transferredto each work station every time it passes the fixed feeding station.

It is another object of this invention to provide an improved assembling machine for cooperating with a transfer mechanism of the type described above to receive a plurality of workpieces at different fixed feeding stations and then assembling the workpieces to form final articles. In this connection, it is a related object of the invention to provide such an assembling machine in which the assembling operation is carried out while the plurality of work stations are continuously rotating.

A further object of the present invention is to provide an improved assembling machine of the foregoing type which includes an inspection station for discriminating between properly and improperly assembled articles and ejecting such articles at appropriate ejection stations before the rotating work stations are returned to the feed stations associated with the transfer mechanism. More particularly, it is an object of this invention to provide such an assembling machine which ejects the assembled articles at either a first or second ejecting station depending upon whether the article is properly or improperly assembled.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which FIGURE 1 is a perspective of one part of an exemplary article to be assembled by the machine of this invention.

FIG. 2 is a perspective of another part of the exemplary article.

FIG. 3 is a longitudinal section through an assembled article including the parts of FIGS. 1 and 2.

FIG. 4 is a plan of a machine constructed according to the invention for assembling the parts of FIGS. 1 and 2 to form the article of FIG. 3.

FIG. 5 is a section taken along the line 5-5 in FIG. 4 and showing one of the assembling tools in the raised position.

FIG. 6 is a fragmentary horizontal section taken along line 6-6 in FIG. 5.

FIG. 7 is a vertical section taken along line 7-7 in FIG. 4.

FIG. 8 is a fragmentary section taken approximately along line 8-8 in FIG. 7.

FIG. 9 is a horizontal section taken along line 99 in FIG. 7.

FIG. 10 is a fragmentary elevation showing the transfer or escapement mechanism for the spring part of FIG. 2.

3,378,907 Patented Apr. 23, 1968 FIG. 11 is a plan of the rejector mechanism with parts broken away to show the internal structure.

FIG. 12 is a fragmentary section taken along line 12- 12 in FIG. 11.

FIG. 13 is a fragmentary section similar to that of FIG. 12 but illustrating a malfunction in the assembling operation.

FIG. 14 is a vertical section taken along line \14-14 in FIG. 11 showing the rejector latch.

FIG. 15 is a perspective of the rejector pawl.

FIG. 16 is a plan similar to that of FIG. 11 but illustrating a malfunction in the assembling operation.

FIG. 17 is a plan similar to that of FIG. 16 but with the parts in a different phase of the rejecting operation.

FIG. 18 is a vertical section similar to a fragment of FIG. 5 illustrating the assembling tool in a lowered position.

FIG. 19 is a perspective of the sensing lever in the machine of FIGS. l-18.

FIG. 20 is a perspective of the rejector in the machine of FIGS. 1-18.

FIG. 21 is a fragmentary plan of the ejector station in the machine of FIGS. 1-18.

FIG. 22 is a perspective of the drive gears for the illustrative machine.

FIG. 23 is a plan of an alternate embodiment of the transfer mechanism shown in FIG. 9.

FIG. 24 is a vertical section taken along line 24-24 in FIG. 23.

While the invention will be described in connection with certain preferred embodiments, it will be understood that it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

Turning now to the drawings, FIGS. 1 through 3 illustrate an exemplary article capable of being assembled by a machine embodying this invention. The completed article shown in FIG. 3 is assembled from the parts of FIGS. 1 and 2, and can be used to join exposed ends of two or more electrical wires to form 'an electrical connection. The article consists of an insulating casing or cup 30 having a tapered coiled spring 32 inserted therein to grip the exposed ends of the wires to be connected and to hold them firmly within the insulating casing and in tight engagement with each other. Articles of this type are well known and provide a quick and convenient means for forming electrical connections without the necessity of soldering or taping. The exposed ends of the wires to be connected are simply inserted into the spring 32 within the insulating cup 30, and the cup is then twisted so as to Wrap the wires into a tight electrical connection and wedging or threading them tightly into the coiled spring.

In order to prevent turning of the spring 32 as the casing 30 is turned relative to the electrical wires inserted therein, the lower or small end of the spring 32 is provided with a lateral extension 34 which fits into one of a plurality of longitudinal slots 36 (FIGS. 3 and 9) formed in the inner sidewalls of the cup 30. To retain the spring 32 longitudinally within the insulating cup 30, the top of the spring is snapped under an inwardly projecting lip or flange 38 also formed on the inner sidewalls of the cup 30. Since articles of this type are: manufactured in large volume and must be sold at a relatively low cost, it will be appreciated that it is important to assemble the parts in a rapid and efiicient fashion so as to achieve high production rates at minimum cost. Of course, this is only one exemplary article which can be assembled by the apparatus of this invention, and it will be apparent from the ensuing discussion that the invention is equally applicable to any number of different operations where one or more workpieces must be handled in a rapid and eflicient manner.

In accordance with one important aspect of the present invention, an escapement mechanism is provided for transferring workpieces from a fixed feeding station to a plurality of continuously rotating work stations, the escapement mechanism comprising a plurality of transfer arms operatively associated with the feeding station and the work stations with the transfer arms being mounted for movement around a circular path which closely approaches both the feeding station and the path of the work stations, and drive means for continuously driving the transfer arms around the circular path and operatively connected to the continuously rotating work stations so as to synchronize the rotation of the transfer arms with the rotation of the work stations whereby a workpiece is transferred to each work station every time a work station passes the escapement mechanism. Each of the transfer arms is provided with a head portion adapted to en gage a workpiece at the feeding station, and control means are associated with the transfer arms for advancing the head of each transfer arm toward the feeding station during each pass, maintaining the head in the advanced position during the transfer from the feeding station to the work station upon continued rotation of the transfer arm, and then immediately retracting the head upon com pletion of the transfer. Thus, referring to the illustrative machine in FIG. 4, two fixed feeding stations indicated generally as PS1 and PS2 are provided for feeding the two parts 30, 32 to a plurality of continuously rotating work stations designated as WSl through W33. The parts 30, 52 are delivered to their respective feeding stations PS1, PS2 along a pair of input channels 40, 41, respectively. A vibratory feeder device which is suitable for advancing the workpieces along the input channels 40, 41 is described in copending application Ser. No. 462,558, filed June 9, 1965, entitled Vibratory Feeding Mechanism, assigned to the assignee of the present invention, but it will be understood that any other suitable feeding mechanism could be used.

Since the transfer mechanisms provided at the two feeding stations PS1, PS2 are of similar construction, only the first transfer mechanism, i.e., the mechanism provided at feed station PS1 to transfer parts 34) from input channel 40 to the work stations WS, will be described in detail herein, and corresponding parts of the transfer mechanism at the second feeding station PS2 will be identified by corresponding reference numerals with the addition of the distinguishing sutfix a. The transfer mechanism for the first feeding station PS1 is shown most clearly in FIGS. 7 and 9, and includes three transfer arms 42 mounted at three equally spaced positions around a rtatable transfer turret 43. As the turret 43 is driven about a fixed shaft 44, the transfer arms 42 follow a circular path which closely approaches both the leading workpiece in the input channel 40 and the path of the advancing work stations WS.

Por the purpose of continuously rotating the transfer arms 42 about their circular path, the transfer turret 43 is journaled on the stationary shaft 44 by means of a pair of ball-bearing assemblies 45, and is secured at its lower end to a main drive gear 46 by means of screws 4-7. To synchronize the rotation of the transfer turret 43 with the continuous rotation of the work stations WS, the main drive gear 46 meshes with a large central gear 48 driven by a pinion 49 (FIG. 22) connected to the main drive for the work station turret to be described below.

As the workpieces 30 are advanced along the input channel 40 by the feeding mechanism, the leading workpiece enters an arcuate transfer channel 59 and is stopped at a predetermined pickup point by means of a positioning element 51. In the particular embodiment illustrated, the positioning element 51 is in the form of a spring detent which is biased to normally project into the channel 5% to stop the leading workpiece 30, and which is retractable to pass the leading workpiece in response to a positive advancing force applied to that workpiece by the transfer mechanism.

In keeping with the present invention, each of the transfer arms 42 is pivotally mounted on the transfer turret 43 and associated with a control cam which swings the head of each transfer arm 42 out into engagement with the leading workpiece 30 each time one of the transfer arms passes the positioning element 51. Continued rotation of the transfer arm then advances the leading workpiece along the arcuate channel 5t}, depressing or retracting the detent 51 momentarily as it passes, and delivers the workpiece to a cooperating work station WS which arrives at the end of the arcuate channel 5% simultaneously with the workpiece that is being transferred Thus, each of the transfer arms 42 is pivotally mounted near the periphery of the turret 43 by means of a screw 52, with a cam follower 53 extending from the trailing side of each screw 52 for cooperation with a fixed control cam 54. The cam 54 is mounted on the fixed shaft 4-4, just above the turret 43, by means of a set screw 54'.

As the transfer turret 43 is rotated, each of the cam followers 53 rides over the cam surface 54, while being urged thereagainst by means of a coil spring 55, so as to control the radial position of the head as of each transfer arm. In other words, each of the cam followers 53 is pivoted about the screw 52 according to the configuration of the cam surface 54. More particularly, the cam surface 54 is cut out at 57 so as to form a first ramp 57' which causes the head 56 of each transfer arm to swing outwardly as it approaches the leading workpiece 30 in engagement with the positioning element 51. The head of the transfer arm remains in its advanced or outer position as long as the cam follower 53 is riding over the cutout 57, i.e., until it reaches the second ramp 57", which is positioned to retract the transfer arm 42 immediately after it delivers the workpiece into the work station WS. The transfer arm then remains in its retracted position until it again approaches the feeding station where the cam follower 53 engages the first ramp 57' on the cam surface. It will thus be recognized that the trans fer arms 42 are continuously rotating in perfect synchronism with the continuously rotating work stations WS so as to urge successive workpieces past the positioning element 51 and into successive work stations WS as they pass the feeding station.

For the purpose of receiving each transferred workpiece 30 from the transfer arms 42, each of the work stations WS1WS8 is provided with a gripping mechanism 66 (FIGS. 8 and 10) comprising a pair of jaws 61 carried on a corresponding pair of spring fingers 62 which bias the jaws 61 together. The spring fingers 62, in turn, are secured to a mounting bracket 62'. The opposed faces 63 of the two jaws 61 are provided with tapered vertical grooves 64 so as to form a socket which is complementally formed with respect to the workpiece 39. Also, the outside corners of the opposed faces 63 are beveled or chamfered as at 65 so that as the head 56 of the transfer arm 42 and the two jaws 61 converge, the workpiece 30 carried by the head 56 engages the beveled corners 65 and pushes the two jaws 61 slightly apart until it snaps into the complementally formed socket The spring action of the two fingers 62 constantly urges the jaws together so as to trap the workpiece 30 within the work station while the transfer arm 42 is retracted by the action of the cam surface 57".

As mentioned previously, the second workpiece 32, which is fed to the work stations WSll-WS8 at the second :feeding station PS2, is transferred from the input channel 41 to the successive work stations by means of an escapement mechanism similar to that described for the first feeding station PS1. Elements of this second escapement mechanism corresponding to similar elements of the first escapemcnt mechanism have been assigned similar reference numerals with the addition of the distinguishing suflix a. To receive the second workpiece 32 from the transfer arms 42a, each work station WSl-WS8 is provided with a sec-0nd gripping mechanism 70 which is located just above the first gripping mechanism 60 in axial alignment therewith. Of course, the second feeding station PS2 must also be located at a higher position than the first feeding station PS1 so as to-cooperate with the second gripping mechanism 70. The upper gripping mechanism 70, which is shown most clearly in FIGS. 9 and 10, comprises a pair of jaws 71 carried by a pair of spring fingers 72 which bias the two jaws together. The spring fingers 72 are secured also to the mounting bracket 62'. In order to form a socket for receiving the workpiece 32, a pair of recesses are formed in the opposed faces of the jaws 71 so that the two jaws cooperate to form a conical socket 73. Also, the outside corners of the opposed jaw faces are beveled in the same manner as the jaws 61 to facilitate entry of the workpieces. Thus, as a work station converges with the escapement mechanism so as to intercept a workpiece 32 carried by one of the transfer arms 42a, the workpiece forces the two jaws 71 apart until it is seated within the socket 73, and then the spring fingers 72 snap the jaws 71 closed to retain the workpiece while the transfer arm 42a is retracted by the cam action described above in connection with the first feeding station.

Thus, it can be seen that each work station WS1-WS8 comprises a pair of vertically alined gripping mechanisms 60, 70 adapted to receive the two workpieces 30, 32 from the escapement mechanisms associated with the two feed stations PS1, PS2. The two gripping mechanisms are supported on a common mounting platform 80 which is rigidly secured to a work station turret 82. The turret S2 is mounted for rotation on a fixed vertical shaft 83 by means of a pair of ball-bearing assemblies 84, and is driven by the main drive pinion 49 meshing with the ring gear 48 secured to the lower end of the turret 82. -It will be recalled that the escapement mechanisms at the two feeding stations F51 and PS2 are also driven by the ring gear 48 via pinions 46, 46a so as to synchronize the rotation of the transfer arms 42, 42a with the rotation of the work stations WS1-WS8. Consequently, each of the transfer arms at the two feeding stations intersects the circular path of the work stations WS precisely when one of the work stations is in alinement with the feeding station so that each work station receives a workpiece every time it passes a feeding station.

In accordance with another aspect of this invention, a plurality of work tools are positioned around the work station turret for rotation therewith, each tool being associated with one of the work stations, and automatic control means are associated with the work tools for cyclically advancing each tool to the associated work station during a portion of each turret revolution and then retracting the tool during the remaining portion of each revolution. Thus, in the illustrative embodiment, eight Work tools 100 are mounted on the upper portion of the turret 82 directly above the eight work stations W51- W88 so that each tool 100 is operatively associated with one work station. Each tool 100 includes a vertical punch rod 101 which is threaded into and carried by a sleeve 102 mounted for vertical movement relative to the turret 82. When the punch rod 101 is lowered, it engages the tapered spring 32 held in the upper gripping device 70 at its associated working station and drives the spring downwardly into the complementally formed cup 30 held in the lower gripping device 60. The punch rod 101 remains in the lowered or advanced position while the turret rotates through a sensing mechanism, which will be described in more detail below, and is then raised to its retracted position clear of the work station.

For the purpose of controlling the vertical movement of the punch rod 101, a cam follower 103 is secured to each vertical sleeve 102, with each cam follower 103 riding over a cooperating suntace 104 on a stationary cam 105. The stationary cam 105 is mounted on a pos t106 extending upwardly from the main turret shaft 83, with the cam 105 being fastened by means of a nut 107 threaded onto the upper end of the post 106. The cam surface 104 which engages the cam followers 103, and thereby controls the vertical movement of the eight tool punch rods 101, is designed to cyclically lower each tool during a portion of each turret revolution when the two workpieces 30, 32 have been received in the associated work stat-ion. The cam holds the punch rod in this lowered position while the turret passes through a sensing mechanism, and is then raised to its retracted position while the work station passes through 1) an ejection mechanism for ejecting the finished product and (2) the two feeding stations PS1, PS2 for receiving a new pair of workpieces 30, 32. Thus, a portion of the cam surface 104 faces downwardly so as to bear against the tops of the cam followers 103 to lower the punch rods during a portion of each turret revolution, whereas the rest of the cam surface faces upwardly in the form of a helical ramp for the purpose of raising the cam followers 103 and maintaining them in such raised position during the balance of each turret revolution.

In order to prevent the punch rod 101 from damaging the workpieces 30, 32 While accounting for variations in the workpiece dimensions, the punch 101 is biased downwardly by means of a coil spring 110 bearing against an annulus 111 secured to the top end of the punch rod and riding within a guide sleeve 112 secured to the top off the cam controlled sleeve 102. The biasing force of the spring 110 is strong enough to permit the punch 101 to drive the tapered spring 32 down into the casing 30 as the sleeve 102 is lowered by the cam control, but the spring 110 also permits the punch 101 to retract slightly within the sleeve 102 in the event the sleeve 102 is still being lowered by the cam control after the work 32 has bottomed out in the workpiece 30. It should be noted that the vertical movement of cam followers 103, and thus the vertical sleeves 102 and 112, is guided by rollers 113 riding in slots 114.

In accordance with a further aspect of this invention, a sensing mechanism is associated with the assembling machine for sensing whether the parts have been correctly assembled and rejecting any products which have been incorrectly assembled. Thus, the punch rod 101 is provided with a horizontal disc which is used to indicate the elevation of the punch rod when it is in its lower-most or advanced position, i.e., when the two parts 30, 32 have been assembled. When the two parts have been correctly assembled, the disc 120 passes freely through a complementally formed horizontal slot in a sensing head 121. This situation is illustrated in FIG. 12 and indicates a correctly assembled product ready for ejection by a mechanism to be described below. When the two par-ts 30, 32 have been incorrectly assembled, the punch rod 101 is higher and if a part is missing it is lower than its normal position and thus the disc 120 does not register with the slot in the sensing head 121. In this case, the disc 120 will engage one of the two faces 122, 123 of the sensing head as illustrated in FIG. 13; the solid line view in FIG. 13 shows the disc 120 is an abnormally high position, engaging the upper face 122 sensing an incorrectly assembled workpiece, whereas the broken lines show the disc is an abnormally low position engaging the lower face 123 indicating the absence of one or both of the parts 30, 32.

In either of the two abnormal positions illustrated in FIG. 13, the disc 120 earns the sensing head 121 away from the tool so as to pivot a lever 124 carrying the sensing head about a pivot point 125, thereby sliding a ramp 126 formed on the opposite end of the lever arm 124 under a cooperating cam surface 127. The cam surface 127 is formed on a plunger 128 which is raised by the pivoting movement of the ramp 126 to (1) depress a spring plunger 129 bearing against the top of the plunger for the purpose of subsequently returning the plunger 128 to its normal position after the disc 120 has cleared the sensing head 121, and (2) to disengage a pawl 130 on the bottom of the plunger 128 from a latch bar 131 for the purpose of actuating a rejector mechanism.

Turning next to the details of the rejector mechanism the release of the latch bar 131 causes a lever 132 on which the latch bar 131 is mounted to be released and swung by a spring plunger 139 about a pivot point 133. This pivoting movement swings the lever 132 from the position shown in FIG. 11 to the position shown in FIG. 16, thereby swinging a bifurcated rejector arm 134 out into the path of the advancing work station. To actuate the rejector arm in its advanced position, so as to disengage and reject the incorrectly assembly product, a cam 135 attached to a pinion gear 136 synchronously driven by the gear 48 sweeps into contact with a roller 137 depending from the lever 132 so as to swing the lever 132 clockwise and thereby snap the incorrectly assembled workpiece into a rejector chute 138 (FIG. 4). This cam action between the cam 135 and the roller 137 also moves the lever 132 back to its original position so that it becomes latched behind the pawl 130 previously returned to its normal retracted position by the action of the spring plunger 129 bearing against the top of the plunger 128.

In those cases where the workpieces are correctly assembled so that the elevation indicating disc 120 registers with the slot in the sensing head 121 and thus passes freely therethrough, the rejector mechanism is not actuated and so the correctly assembled product continues to be carried around by the turret until it reaches an ejector mechanism which removes the acceptable product and ejects it into a final product chute 140 (FIGS. 4 and 21). The ejector consists of a single stationary bifurcated lever 141 which intersects the path of the advancing Work station so as to engage the finished products within the lower gripping mechanism and cam them into the final product chute 140. Of course, if the article has been incorrectly assembled so that a work station is empty when it arrives at the ejector mechanism, the work station simply passes over the stationary lever 141 and continues on to receive the next pair of workpieces at the feeding stations PS1 and PS2.

In FIGS. 23 and 24, an alternative embodiment of the escapement mechanism employed at the two feeding stations is illustrated with parts corresponding to those previously described having the same reference numerals with the addition of a distinguishing suffix 12. Thus, a transfer mechanism similar to that shown in FIG. 9 is illustrated in FIGS. 23 and 24 with arms 42b carrying cam followers 200 in the form of rollers journaled on the arms for intercepting the workpiece and transferring it to a gripping mechanism on the work station turret. The arms 42b are carried in a spider 202 bolted to a shaft 204 rotatably driven on hearing 206 by a pinion 471;. Each arm 42b is pivoted to the spider at 52b and has a head portion 210 carrying two downwardly projecting prongs 212 to engage the workpiece to be transferred. For the purpose of biasing the head portion and the cam follower vertically toward a horizontal cam surface 214, a spring 216 is mounted between a projection 218 of each arm 42b and the spider. Thus, when the cam follower on any given arm 42b reaches the low point of the cam surface, the head 210 is biased down into contact behind a workpiece 3012. Then as the pinion 4712 continues to rotate, the two prongs 212 advance the workpiece along the arcuate channel 50b into engagement with the advancing work station where the workpiece is received in a suitable gripping mechanism.

As can be seen from the foregoing detailed description, the present invention provides an improved transfer mechanism, or escapement mechanism, for transferring individual workpieces from a fixed feeding station to a plurality of continuously rotating work stations. The transfer mechanism operates continuously in synchronism with the continuously rotating stations so that a workpiece is continually transferred to each work station every time it passes the fixed feeding station. This invention also provides an improved assembling machine for cooperating with such a transfer mechanism to receive a plurality of workpieces at different fixed feeding stations and then assembling the workpieces to form final articles. The machine also includes an inspection station for discriminating between properly and improperly assembled articles and ejecting such articles at appropriate ejecting stations before the rotating work stations are returned to the feed stations associated with the transfer mechanism. More particularly, the inventive machine ejects the assembled articles at either a first or second ejecting station depending upon whether the article is properly or improperly assembled.

I claim as my invention:

1. An escapement mechanism for transferring work pieces from a fixed feeding station to a plurality of continuously rotating work stations, said escapement mechanism comprising a plurality of transfer arms operatively associated with said feeding station and said work stations, said transfer arms being mounted for movement around a circular path which closely approaches said feeding station and the path of said work stations, each of said transfer arms having a head portion adapted to engage a workpiece at said feeding station whereby the workpiece is transferred from said feeding station to the path of said work stations upon continued movement of said transfer arms, drive means for continuously driving said transfer arms around said circular path, said drive means being operatively connected to said continuously rotating work stations so as to synchronize the rotation of said transfer arms with the rotation of said work stations whereby a workpiece is transferred to each work station upon every pass of the work station by said transfer arms, and control means associated with said transfer arms for advancing the head of each transfer arm toward said work station during each pass, maintaining said head in the advanced position during the tranfer from the feeding station to the work station, and then immediately retracting said head upon completion of the transfer.

2. An assembly machine comprising the combination of a rotatable turret, a plurality of work station mounted on said turret and positioned at substantially equal angular intervals around the periphery of the turret, each work station including a pair of vertically alined gripping devices for receiving and holding a pair of workpieces, a plurality of work tools mounted on said turret above said work stations with each tool being associated with one work station, said tools being mounted for vertical movement toward and away from the associated work stations, and a control cam operatively connected to said work tools for controlling the vertical movement of the tools so that each tool is lowered into engagement with the workpieces at its associated work station during a portion of each turret revolution and then raised clear of its work station during another portion of each turret revolution.

3. A machine tool comprising the combination of a rotatable turret, a plurality of work stations positioned around said turret for rotation therewith, each work station including means for holding at least one workpiece, a plurality of transfer arms operatively associated with said feeding station and said work stations, said transfer arms being mounted for movement around a circular path which closely approaches said feeding station and the path of said work stations, each of said transfer arms having a head portion adapted to engage a workpiece at said feeding station whereby the workpiece is transferred from said feeding station to the path of said work stations upon continued movement of said transfer arms, drive means for continuously driving said transfer arms around said circular path, said drive means being operatively connected to said continuously rotating work stations so as to synchronize the rotation of said transfer arms with the rotation of said work stations whereby a workpiece is transferred to each work station upon every pass of the work station by said transfer arms, control means associated with said transfer arms for advancing the head of each transfer arm toward said feeding station during each pass, maintaining said head in the advanced position during the transfer from the feeding station to the work station, and then immediately retracting said head upon completion of the transfer, a plurality of work tools positioned around said turret for rotation therewith, each work tool being associated with one of said work stations, and control means associated with said work tools for cyclically advancing each tool into engagement with the workpiece at the associated work station during a portion of each turret revolution and retracting the tool during another portion of each turret revolution.

4. In a machine tool including a rotatable turret and means for continuously driving said turret, the combination of a plurality of work stations positioned around said turret for continuous rotation therewith, each work station including at least one gripping device for receiving and holding a workpiece, a feeding station including means for advancing a plurality of workpieces in seriatim to a fixed feed position, and transfer mechanism having at least one continuously rotatable transfer element for transferring workpieces from said feed position to the continuously rotating work stations, means for continuously driving said transfer element in synchronism with the continuous rotation of said work stations, and control means operatively associated with said transfer element for advancing the element to engage the lead workpiece each time the element passes said fixed feed position and to transfer the engaged workpiece to one of the work stations upon continued rotation of the transfer element, said control means retracting said transfer element upon the completion of each workpiece transfer.

5. An assembly machine comprising the combination of a rotatable turret, a plurality of work stations mounted on said turret and positioned at substantially equal angular intervals around the periphery of the turret, each work station including a pair of vertically alined gripping devices for receiving and holding a pair of workpieces, a plurality of transfer arms operatively associated with said feeding station and said work stations, said transfer arms being mounted for movement around a circular path which closely approaches said feeding station and the path of said work stations, each of said transfer arms having a head portion adapted to engage a workpiece at said feeding station whereby the workpiece is transferred from said feeding station to the path of said work stations upon continued movement of said transfer arms, drive means for continuously driving said transfer arms around said circular path, said drive means being operatively connected to said continuously rotating Work stations so as to synchronize the rotation of said transfer arms with the rotation of said work stations whereby a workpiece is transferred to each work station upon every pass of the work station by said transfer arms, control means associated with said transfer arms for advancing the head of each transfer arm toward said feeding station during each pass, maintaining said head in the advanced position during the transfer from the feeding station to the work station, and then immediately retracting said head upon completion of the transfer, a plurality of work tools mounted on said turret above said work stations with each tool being associated with one work station, said tools being mounted for vertical movement toward and away from the associated work stations for assembling said workpieces, and a control cam operatively associated with said work tools for controlling the vertical movement of the tools so that each tool is lowered into engagement with the workpieces at its associated work station during a first portion of each turret revolution and then raised clear of its work station during a second portion of each turret revolution.

6. An assembly machine comprising the combination of a rotatable turret, a plurality of work station mounted on said turret and positioned at substantially equal angular intervals around the periphery of the turret, each work station including a pair of vertically alined gripping devices for receiving and holding a pair of workpieces, a plurality of transfer arms operatively associated with said feeding station and said work stations, said transfer arms being mounted for movement around a circular path which closely approaches said feeding station and the path of said work stations, each of said transfer arms having a head portion adapted to engage a workpiece at said feeding station whereby the workpiece is transferred from said feeding station to the path of said work stations upon continued movement of said transfer arms, drive means for continuously driving said transfer arms around said circular path, said drive means being operatively c0nnected to said continuously rotating work stations so as p to synchronize the rotation of said transfer arms with the rotation of said work stations whereby a workpiece is transferred to each work station upon every pass of the work station by said transfer arms, control means associated with said transfer arms for advancing the head of each transfer arm toward said feeding station during each pass, maintaining said head in the advanced position during the transfer from the feeding station to the work station, and then immediately retracting said head upon completion of the transfer, a plurality of work tools mounted on said turret above said work stations with each tool being associated with one work station, said tools being mounted for vertical movement toward and away from the associated work stations for assembling said workpieces, each of said tools including an elevation indicating means, a control cam operatively associated with said work tools for controlling the vertical. movement of the tools so that each tool is lowered into engagement with the workpieces at its associated work station during a first portion of each turret revolution and then raised clear of its work station during a second portion of each turret revolution, and a sensing station for sensing whether the workpieces are correctly assembled by a tool in its lowered position, said sensing station including control means responsive to said elevation indicating means on said tools for sensing and rejecting any incorrectly assembled workpieces.

7. In a machine for assembling two workpieces, the combination comprising a frame, a gear journaled to said frame, means for transmitting energy to said gear, means mounted on said gear for gripping one of the workpieces in a spaced vertical alinement with the other workpiece, means for positioning the workpieces at two locations adjacent to said gripping means, a cam mounted on said frame, transfer arms rotatably mounted adjacent to said cam each having a head portion for removing the workpieces from one of said locations, cam followers on said transfer arms adapted to ride on said cam, means for biasing said followers toward said 0am, means for rotating said transfer arms relative to said cam, said rotating means being adapted to move synchronously with said gear, assembly means for pushing one of the workpieces vertically into the other of the workpieces to assemble the same, means for sensing the correct performance of said assembly, means responsive to said sensing means for rejecting any workpieces incorrectly assembled, and means for ejecting all correctly assembled workpieces.

'8. A mechanism for transferring workpieces comprising a continuously rotating platform including a plurality of angularly spaced work stations, a feeding station including a workpiece positioning mechanism, a cam located adjacent to the platform and to said mechanism, a pinrality of arms rotata'bly mounted adjacent to said cam each having a head portion, a cam follower on each of said arms adapted to ride on said cam, means for biasing said follower toward said cam, means for continuously rotating said arms relative to said cam whereby the workpieces are continually transferred from said positioning mechanism to the work stations on said continuously rotating platform.

9. In a machine for assembling two workpieces, the combination comprising a frame, a gear journaled to said frame, means for transmitting energy to said gear, means mounted on said gear for gripping the two workpieces vertically spaced from and alined with each other, means for positioning the workpieces at two locations adjacent to said gripping means, means for continuously transferring the workpieces from said locations to said gripping means, a vertically mova ble sleeve mounted on said gear adjacent to said gripping means, a cam fixed relative to said gear, a cam follower on said sleeve adapted to engage said cam, a tool mounted on said sleeve for pushing one of the workpieces vertically into the other workpiece, means for sensing the correct assembly of the workpieces, means responsive to said sensing means for rejecting any workpieces incorrectly assembled, means for receiving such rejected workpieces, fixed means for ejecting all workpieces correctly assembled, and means for receiving the same.

10. In a machine for assembling two workpieces, the combination comprising a frame, a gear journaled to said frame, means for transmitting energy to said gear, means mounted on said gear for gripping the two workpieces vertically spaced from and alined with each other, an assembly tool for pushing one of the workpieces vertically into the other of the workpieces, a camming surface on said tool, .a lever pivoted relative to said tool and having a sensing head, said head having an opening to accommodate said camming surface without pivoting and a surface adapted to abut said camming surface to pivot s'aid lever, a rejector and means for biasing said rejector toward the assembled workpieces, means responsive to the ivoting of said lever for releasing said rejector to an armed position, means responsive to said gear for actuating said rejector when in said armed position, and means for ejecting all workpieces not rejected by said rejector.

References Cited UNITED STATES PATENTS 3,064,338 11/1962 Holoubek et a1 29-203 3,121,281 2/1964 Petro 29-203 3,289,283 12/1966 Muller 29203 THOMAS H. EAGER, Primary Examiner. 

1. AN ESCAPEMENT MECHANISM FOR TRANSFERRING WORKPIECES FROM A FIXED FEEDING STATION TO A PLURALITY OF CONTINUOUSLY ROTATING WORK STATIONS, SAID ESCAPEMENT MECHANISM COMPRISING A PLURALITY OF TRANSFER ARMS OPERATIVELY ASSOCIATED WITH SAID FEEDING STATION AND SAID WORK STATIONS, SAID TRANSFER ARMS BEING MOUNTED FOR MOVEMENT AROUND A CIRCULAR PATH WHICH CLOSELY APPROACHES SAID FEEDING STATION AND THE PATH OF SAID WORK STATIONS, EACH OF SAID TRANSFER ARMS HAVING A HEAD PORTION ADAPTED TO ENGAGE A WORKPIECE AT SAID FEEDING STATION WHEREBY THE WORKPIECE IS TRANSFERRED FROM SAID FEEDING STATION TO THE PATH OF SAID WORK STATIONS UPON CONTINUED MOVEMENT OF SAID TRANSFER ARMS, DRIVE MEANS FOR CONTINUOUSLY DRIVING SAID TRANSFER ARMS AROUND SAID CIRCULAR PATH, SAID DRIVE MEANS BEING OPERATIVELY CONNECTED TO SAID CONTINUOUSLY ROTATING WORK STATIONS SO AS TO SYNCHRONIZE THE ROTATION OF SAID TRANSFER ARMS WITH THE ROTATION OF SAID WORK STATIONS WHEREBY A WORKPIECE IS TRANSFERRED TO EACH WORK STATION UPON EVERY PASS OF THE WORK STATION BY SAID TRANSFER ARMS, AND CONTROL MEANS ASSOCIATED WITH SAID TRANSFER ARMS FOR ADVANCING THE HEAD OF EACH TRANSFER ARM TOWARD SAID WORK STATION DURING EACH PASS, MAINTAINING SAID HEAD IN THE ADVANCED POSITION DURING THE TRANSFER FROM THE FEEDING STATION TO THE WORK STATION, AND THEN IMMEDIATELY RETRACTING SAID HEAD UPON COMPLETION OF THE TRANSFER. 